QST: why do we compute hash here

[danielhrisca]

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Question about pandas

In pandas.core.indexes.base hash is called here and the value is not used.

Why is this done?

[jreback]

so we get the right kind of error on unhashables. simpler to do it here than directly in the indexing code.

In [29]: 1 in pd.Index([1, 2])                                                                                                                                   
Out[29]: True

In [30]: [] in pd.Index([1, 2])                                                                                                                                  
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-30-aed417339954> in <module>
----> 1 [] in pd.Index([1, 2])

/home/tsdist/vats_deployments/modeling.env.interactive-4d8c1c87-b253-4083-a330-ac480ba587f4/ts/modeling/environment/interactive/../../../../ext/public/python/pandas/1/0/5/dist/lib/python3.6/pandas/core/indexes/numeric.py in __contains__(self, key)
    230         Check if key is a float and has a decimal. If it has, return False.
    231         """
--> 232         hash(key)
    233         try:
    234             if is_float(key) and int(key) != key:

TypeError: unhashable type: 'list'

[danielhrisca]

Thank you for the details!